Cbi in-tab bending device to which position measuring unit is added

Abstract

The present invention provides an electrode tab bending device, which is an anode tab bending device of a jelly roll electrode assembly having a cathode tab and an anode tab, the device comprising: a jig for holding the jelly roll electrode assembly such that the anode tab can be lifted upward; a pressurizing tool for pressurizing the anode tab from top to bottom; a spindle device for vertically moving the pressurizing tool; and a position measurement unit for measuring the upper and lower positions of the pressurizing tool.

Description

CBI IN-TAB bending device with position measuring unit

[0001] The present invention relates to a CBI In-Tab bending device with an added position measuring unit. Specifically, the present invention relates to a CBI In-Tab bending device with an added position measuring unit that measures the position of a pressurizing mechanism used when bending a negative tab at the bottom of a jelly roll electrode assembly by 90 degrees.

[0002] A lithium secondary battery includes an electrode assembly including a positive electrode coated with a positive electrode active material, a negative electrode coated with a negative electrode active material, a separator positioned between the positive electrode and the negative electrode to prevent short circuiting and enable movement of lithium ions (Li-ions), a battery case that accommodates the electrode assembly, and an electrolyte that is injected into the inside of the battery case to enable movement of lithium ions.

[0003] Lithium secondary batteries are classified into cylindrical or prismatic batteries, which house the electrode assembly in a cylindrical or prismatic metal can, and pouch batteries, which house the electrode assembly in a pouch-shaped case made of aluminum laminate sheet, depending on the shape of the battery case. Cylindrical batteries have the advantages of relatively large capacity and structural safety.

[0004] Cylindrical batteries are manufactured by placing and sealing a jellyroll electrode assembly, which is wound with a separator sheet interposed between a positive electrode sheet and a negative electrode sheet, in a cylindrical battery case. The jellyroll electrode assembly is placed inside a cylindrical can, and the negative electrode tab located on the bottom of the cylindrical can and the lower part of the jellyroll electrode assembly are welded.

[0005] Before placing the jellyroll electrode assembly into a cylindrical can, a cylindrical bottom insulator (hereinafter referred to as "CBI") is added to the bottom of the jellyroll electrode assembly to insulate it from the cylindrical can. The jellyroll electrode assembly is turned over so that the negative tab is at the top, and then the negative tab is bent 90 degrees using a pressing mechanism. Before proceeding with the bending, the negative tab (In-Tab) is first aligned to match the position of the pressing mechanism.

[0006] Figure 1 is a top view of a CBI In-Tab bending device according to the prior art.

[0007] Referring to Fig. 1, alignment of the negative tab (In-Tab) is required before feeding it into the CBI In-Tab bending device. Before bending the jelly roll electrode assembly inherited from the previous process, the negative tab (In-Tab) is aligned to match the position of the pressurizing mechanism. Fig. 1 shows three rotating devices. The first rotating device (100) is a rotating device that can accommodate and perform work on 16 jelly roll electrode assemblies. The first rotating device (100) and the second rotating device (200) are devices that align the negative tab (In-Tab) to match the position of the pressurizing mechanism. The device for aligning the electrode tab is a technology known from patent documents 4 and 5, etc., and the present invention uses a jelly roll electrode assembly in which the electrode tab, specifically the negative tab, has already been aligned, and therefore a description thereof is omitted.

[0008] When the jellyroll electrode assembly is wound, the negative electrode tab and the positive electrode tab protrude from the upper or lower surface of the circular shape of the wound electrode assembly. However, the position at which the electrode tab protrudes may be the outermost, middle, or innermost point of the jellyroll electrode assembly. These positions vary depending on the notching positions of the tabs when manufacturing the electrode assembly. Meanwhile, the negative electrode tab and the positive electrode tab may be configured in multiple numbers. When the position at which the electrode tab protrudes is in the middle, this is called an In-Tab. The present invention specifically relates to a case where there is one negative electrode tab and it is an In-Tab.

[0009] The aligned jelly roll electrode assembly is transferred to the third and final rotary device (300), and the negative tab is bent 90 degrees in the CBI In-Tab bending device. In Fig. 1, this tool is indicated as a spindle tool (310). As described above, the positive tab and the negative tab of the jelly roll electrode assembly protrude based on the upper or lower surface of the rolled electrode assembly circle. The jelly roll electrode assembly, which is vertically erected with the negative tab facing upward, is bent in the negative tab by a pressing mechanism in the last rotary device (300).

[0010] If the negative tab is placed vertically, the negative tab will not bend as the bending mechanism moves downward from the top, but will deform in a zigzag pattern or only partially fold, which may cause problems.

[0011] Due to this issue, the pressurizing mechanism, prior to pressurizing the negative tab (In-Tab), slightly angles the end of the negative tab as a preliminary step. By pressing the center of the angled negative tab, the pressurizing mechanism can naturally bend the entire negative tab 90 degrees.

[0012] The device according to Fig. 1 is capable of continuously operating a plurality of jelly roll electrode assemblies without stopping. Therefore, if the operating conditions are not improved, a large number of defective products may be produced.

[0013] The bending angle varies depending on the depth of the pressurizing device. If the pressurizing device is pressed too shallowly, the bending will not be completed, preventing the negative tab from bending at a 90-degree angle. When inserting this jellyroll electrode assembly into a cylindrical can, defects may occur during the welding process of the negative tab.

[0014] If the pressing force of the pressurizing device is too deep, the negative tab itself, which is supposed to be bent, may become distorted. While many defects occur when the electrode tabs are not properly aligned during the pre-bending process, the depth of the pressing force also contributes to many defects.

[0015] Despite these issues, conventional CBI In-Tab bending devices do not measure the depth of the pressurizing mechanism. Measuring, comparing, and improving the depth of the pressurizing mechanism's position can improve product quality and reduce defect rates. However, prior technology appears to have failed to recognize this problem. Specifically, the pressurizing mechanism moves up and down via a spindle, but this movement is not measured.

[0016] Patent Document 1 discloses a device that performs tasks such as aligning tabs by placing a can (20) with a jelly roll (10) inserted into a transport carrier (30) with the upper and lower sides open, but does not have a spindle for aligning the tabs of the jelly roll and does not have a height sensor for measuring the position of the spindle.

[0017] Patent Document 2 includes a lead (3) connecting an electrode group (14) and a sealing plate (2), and discloses a technology in which an upper spindle (7) is lowered from the upper portion of a cylindrical battery case (1) to guide and assemble the sealing plate (2) into the opening (1a) of the battery case in order to assemble the sealing plate (2) into the opening of the cylindrical battery case (1), but there is a difference in that it is not a technology for bending an electrode tab, but rather a technology for lowering the upper spindle (7) to assemble the sealing plate (2) into the case (1).

[0018] Patent document 3 discloses a press device including a slide position detection means (8) that moves up and down by a slide driving means (2) and measures the height of a slide (4) that performs press processing, but the technology is different in that it is not a technology for bending an electrode tab and is used in a hydraulic press device.

[0019] In this way, a separate position measurement technology for the pressurization depth of the pressurization device has not been presented, and it appears that the defects that may arise from this have not been recognized.

[0020] Republic of Korea Patent Publication No. 0486149 ('Patent Document 1')

[0021] Japanese Patent Publication No. 1997-167602 (Patent Document 2)

[0022] Republic of Korea Patent Publication No. 2018-0046403 (Patent Document 3)

[0023] Republic of Korea Patent Publication No. 0145206 ('Patent Document 4')

[0024] Republic of Korea Patent Publication No. 0148933 ('Patent Document 5')

[0025] The present invention is intended to solve the above problems, and provides a CBI In-Tab bending device having a position measuring unit for measuring the position of a pressurizing mechanism used to bend a negative tab at the bottom of a jelly-roll electrode assembly by 90 degrees, a jelly-roll electrode assembly bent by the CBI In-Tab bending device, a cylindrical battery including the bent jelly-roll electrode assembly, and a method for bending a negative tab at the bottom of a jelly-roll electrode assembly by 90 degrees using the CBI In-Tab bending device.

[0026] In order to achieve the above purpose, the present invention provides an electrode tab bending device for a jelly roll electrode assembly having a positive electrode tab and a negative electrode tab, the device including a jig for holding the jelly roll electrode assembly so that the negative electrode tab can be raised, a pressing mechanism for pressing the negative electrode tab from top to bottom, a spindle device for moving the pressing mechanism up and down, and a position measuring unit for measuring the vertical position of the pressing mechanism.

[0027] In the present invention, the spindle refers to a mechanism that moves up and down by riding a cam, and the negative tab according to the present invention is typically located at the bottom of a cylindrical can.

[0028] The above position measuring unit may include a measuring dog attached to the upper surface of the pressurizing mechanism and a displacement sensor that measures the height of the measuring dog, and the displacement sensor may be fixed to a separate bracket.

[0029] The displacement sensor may be a laser displacement sensor. A laser displacement sensor is a sensor that emits a laser from the sensor's light-emitting portion and reads displacement through the reflected laser. However, any sensor capable of measuring displacement is sufficient, and is not necessarily limited to a laser displacement sensor. The negative tab is an In-Tab.

[0030] When the pressurizing mechanism presses the negative tab, it may pressurize the side surface of the middle portion of the negative tab. Before the pressurizing mechanism presses the negative tab, at least a portion of the negative tab is deformed to an inclined state. This may be performed by a device provided in the previous step.

[0031] When the jelly roll electrode assembly is placed on the jig, it may be placed on the jig with the direction of the negative tab aligned with the pressing surface of the pressing mechanism. The alignment may be performed by the in-tap alignment device provided in the previous step.

[0032] The present invention also provides a method for bending a negative tab of a jelly roll electrode assembly using an electrode tab bending device according to the present invention, which includes a first step of mounting a jelly roll electrode assembly on a jig so that the negative tab can be raised, and a second step of pressing the negative tab from top to bottom using a pressing mechanism, wherein the second step is performed simultaneously with a step of measuring the upper and lower positions of the pressing mechanism using the position measuring unit.

[0033] The present invention also provides a jelly roll electrode assembly in which a negative electrode tab is bent by an electrode tab bending device.

[0034] The present invention provides a cylindrical battery including a jelly roll electrode assembly according to the present invention.

[0035] The present invention can also provide a problem solving means by arbitrarily combining the above problem solving means.

[0036] The present invention provides an electrode tab bending device for a jelly roll electrode assembly having a positive electrode tab and a negative electrode tab, the device including a jig for holding the jelly roll electrode assembly so that the negative electrode tab can be raised, a pressing mechanism for pressing the negative electrode tab from top to bottom, a spindle device for moving the pressing mechanism up and down, and a position measuring unit for measuring the vertical position of the pressing mechanism.

[0037] The present invention has the effect of reducing the defect rate in CBI In-Tab bending by measuring the position of a pressure mechanism in a cathode tab bending device.

[0038] Figure 1 is a top view of a CBI In-Tab bending device according to the prior art.

[0039] Figure 2 is a top view of the CBI In-Tab bending device according to the present invention.

[0040] Figure 3 is a schematic diagram of displacement measurement of a pressurizing mechanism in a CBI In-Tab bending device according to the present invention.

[0041] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those with ordinary skill in the art can easily implement the present invention. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0042] Additionally, the same drawing reference numerals are used for parts with similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless specifically stated otherwise, but rather implies the inclusion of additional components.

[0043] Additionally, the description that concretizes or adds components may be applied to all inventions unless there are special limitations, and is not limited to the description of a specific invention.

[0044] Additionally, throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0045] Additionally, throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0046] Additionally, all numerical ranges include the extreme values ​​and all intermediate values ​​between them, unless explicitly stated otherwise.

[0047] The present invention is described in detail with examples according to the drawings.

[0048] Fig. 2 is a top view of a CBI In-Tab bending device according to the present invention, and Fig. 3 is a schematic diagram for measuring displacement of a pressurizing mechanism in a CBI In-Tab bending device according to the present invention.

[0049] Fig. 1 is a top view of a CBI In-Tab bending device according to the prior art, and Fig. 2 is a device in which a measuring dog (320), a displacement sensor (330), and a bracket (400) are added to Fig. 1.

[0050] The spindle tool (310) mentioned in FIGS. 1 and 3 is configured to include a spindle (315) and a pressurizing mechanism (340). Referring to FIG. 3, the present invention is an electrode tab bending device including a jig (500) for holding a jelly roll electrode assembly (10) having a positive tab (14) and a negative tab (12) so that the negative tab (12) can be raised, a pressurizing mechanism (340) for pressing the negative tab (12) from top to bottom, a spindle (315) for moving the pressurizing mechanism (340) up and down, and a position measuring unit (600) for measuring the vertical position of the pressurizing mechanism (340). The position measuring unit (600) includes a measuring dog (320) and a displacement sensor (330). In the present invention, the spindle (315) refers to a mechanism that moves up and down by riding a cam, and the negative tab (12) according to the present invention is typically located at the bottom of a cylindrical can.

[0051] The above position measuring unit (600) includes a measuring dog (320) attached to the upper surface of the pressurizing mechanism (340), and a displacement sensor (330) that measures the height of the measuring dog (320). The displacement sensor (330) is fixed to a separate bracket (400). The displacement sensor (330) is a laser displacement sensor. The laser displacement sensor is a sensor that reads displacement by emitting a laser from the light-emitting unit of the sensor and reflecting the laser back. Meanwhile, the negative tab (12) is an in-tab.

[0052] The left side (lower side) of Fig. 3 is a schematic diagram before the pressurizing mechanism (340) presses the negative tab (12), and the right side (upper side) of Fig. 3 is a schematic diagram after the pressurizing mechanism (340) presses the negative tab (12). The right side of Fig. 3 shows the pressurizing mechanism (340) and the negative tab (12) in duplicate to help understanding. The position measurement values ​​D1 and D2 are the positions of each pressurizing mechanism (340), which are quantitative data on how much the pressurizing mechanism actually presses. With just the difference in the position measurement values, it is easy to determine whether the negative tab is properly bent, and only the device where a defect occurs can be identified. The range in which bending is normal can also be determined, which can significantly improve the quality. The CBI In-Tab bending device according to the present invention has already been applied to an actual cylindrical battery manufacturing process, contributing greatly to improving the quality of the product.

[0053] Anyone with ordinary knowledge in the field to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0054] (Explanation of symbols)

[0055] 10: Jellyroll electrode assembly

[0056] 12: Negative tab

[0057] 14: Positive tab

[0058] 100: First rotary device

[0059] 200: Second rotary device

[0060] 300: Third rotary device

[0061] 310: Spindle tool

[0062] 315: Spindle

[0063] 320: Measuring dog

[0064] 330: Displacement sensor

[0065] 340: Pressurizing mechanism

[0066] 400: Bracket

[0067] 500: Jig

[0068] 600: Position measurement unit (320, 330)

[0069] D1, D2: Position measurement values

Claims

1. In a negative tab bending device of a jelly roll electrode assembly having a positive tab and a negative tab, A jig for holding the jelly roll electrode assembly so that the negative tab can be positioned upward; A pressurizing mechanism that pressurizes the negative tab from top to bottom; A spindle device for moving the above pressurizing mechanism up and down; A position measuring unit for measuring the upper and lower positions of the above pressurizing mechanism; An electrode tab bending device including:

2. In paragraph 1, The above position measuring unit, A measuring dog attached to the upper surface of the above pressurizing device; A displacement sensor that measures the height of the above measuring dog; An electrode tab bending device including:

3. In paragraph 2, The above displacement sensor is an electrode tab bending device fixed to a separate bracket.

4. In paragraph 2, The above displacement sensor is an electrode tab bending device that is a laser displacement sensor.

5. In paragraph 1, The above negative tab is an electrode tab bending device called In-Tab.

6. In paragraph 1, An electrode tab bending device that pressurizes a side surface of the middle portion of the negative tab when the pressurizing mechanism pressurizes the negative tab.

7. In paragraph 1, An electrode tab bending device that is mounted on a jig so that the direction of the negative tab is aligned with the pressurizing surface of the pressurizing mechanism when the jelly roll electrode assembly is mounted on the jig.

8. Step 1: Mounting the jelly roll electrode assembly on the jig so that the negative tab is on top; Step 2: Pressurizing the negative tab from top to bottom using a pressurizing device: A method for bending a negative tab of a jelly roll electrode assembly using an electrode tab bending device according to any one of claims 1 to 7, The second step is a jelly roll electrode assembly negative tab bending method that is performed simultaneously with a step of measuring the upper and lower positions of the pressurizing mechanism using the position measuring unit.

9. A jelly roll electrode assembly in which the negative tab is bent by an electrode tab bending device according to any one of clauses 1 to 7.

10. A cylindrical battery comprising a jelly roll electrode assembly according to Article 9.

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